OPERATION
The Synthesized MPI-II Personal Radio is designed to
provide personal communications in a lightweight, handheld
unit. There are two versions available, a two watt and a four
watt. The description of operation is the same for both ver-
sions. Each radio is equipped with two Accessory Jacks to
allow connections of external audio devices and program-
ming of radio information through a personal computer and
PC programming software.
Each communications channel can be programmed for
tone or digital Channel Guard Encode/Decode operation and
Talk-Around/Type 99 Tone operation. Carrier Control Timer,
Global Alert Beep, and Squelch Tail Elimination are pro-
grammed on a per radio basis.
CONTROLS
ON/OFF/VOL
The ON/OFF/VOL knob located on
the top of the radio controls power
from the battery pack to the radio
and adjusts the volume level.
SQUELCH
The SQUELCH knob located on the
top of the radio is used to set the Sig-
nal-To-Noise level required to open
the speaker. This level is normally
set around 8 dB SINAD.
OPTION SW
The OPTION SWITCH is a three po-
sition toggle switch located on the
top of the radio. It performs the fol-
lowing functions:
1. With the toggle switch toward the
front of the radio, all tone de-
codes (CG, DCG, Type 99) are
disabled.
2. With the toggle switch in the
middle position, tone decode is
enabled and Type 99 Decode is in
the Selective Mode. In this mode
an incoming call will open
the audio and Type 99 Decode is
in Monitor Mode. To reset the
Type 99 Decode to Selective
Mode, move the toggle switch to
the rear position and back to the
middle.
3. With the toggle switch toward the
rear of the radio, the radio will be
in one of two states:
Talk-Around: The radio will now
transmit on the programmed re-
ceive frequency. This enables one
to "Talk-Around" a repeater.
T99 Monitor: If the radio is in-
stead programmed for Type 99
Decode, this will put the radio in
Type 99 Monitor Mode. In this
mode, audio will open for any on
channel RF signal with the cor-
rect Channel Guard tone. An in-
coming call will alert the user
by beeping, and Type 99 Decode
will stay enabled to receive the
next call.
CHANNEL
SELECTOR
Selects the transmit/ receive chan-
nel(channel 1 or channel 2).
PTT
Keys the radio on the communica-
tion channel selected.
TO RECEIVE A MESSAGE
1. Turn the OFF-VOLUME control clockwise to about
mid-range.
2. Disable any option by placing the option control tog-
gle switch in the front or "MON" POSITION.
3. Turn the SQUELCH (SQ) control fully clockwise. A
hissing sound will be heard from the speaker.
4. Adjust the VOLUME control until the hissing sound
is easily heard but not annoyingly loud.
5. Turn the SQUELCH control slowly counterclockwise
until the hissing noise stops. This adjustment is very
important as it eliminates annoying noise when no
one is calling. It also determines how sensitive the ra-
dio will be to incoming calls. In Channel Guard and
Type 99 operation, battery life will be degraded if the
squelch control is not set in this way.
6. Select the proper channel. Place the option switch in
the appropriate position for the desired decoding
function. All is now ready to receive messages from
other radios in the system.
Figure 2 - Operating Controls
LBI-38558
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